Storage and display shelves which are mounted on a powered carousel to allow a user to selectively position a shelf within easy reach or within view are known. These devices generally mount the shelves on tracks arranged at either end of the shelf and provide a drive means such as a powered cable or chain for driving the shelves around the tracks. An actuating means is usually provided which allows a user to move the shelves around the track until a desired shelf comes within reach or view.
Large vertical shelf carousels of this type are known for use in industrial applications. Having the shelves mounted on the carousel enables an individual to access all of the shelves without the use of a ladder or other elevating device, and provides a large number of shelves for a given square footage of floor space. To further increase the efficiency of these devices the shelves are generally spaced along the drive means in close proximity to one another so that the bottom of an upper shelf lies close to the top of the lower shelf. This can lead to difficulty in gaining access to an object on the shelf, particularly when the object is nearly as large as the space between the shelves. A second problem associated with these shelves is that since the shelves must be able to travel in a loop about a vertical frame, a turn in the track is necessary at both the top and bottom of the carousel. As a shelf moves through a turn there can be a tendency for the shelf to swing or tip. This may result in an item falling off the shelf which is dangerous and can lead to serious injury. This is particularly true for shelves used to store heavy items.